Simulation of Rolling Contact Fatigue Strength for Traction Drive Elements

Abstract

A simulation of the rolling contact fatigue strength of a traction drive element was proposed. The simulation can account for both the distribution of sizes of inclusions in the element material and the influence of traction forces at the element surface. The shear strength of the matrix structure surrounding an inclusion was estimated with an equation. The hardness distribution and the Weibull distribution of inclusion dimensions, which were necessary parameters to calculate the rolling contact fatigue strength, were determined by observation of an actual test specimen. And the rolling contact fatigue strength was compared with the distribution of shear stresses in a roller affected by traction forces. A simulation assuming the same traction coefficient as that in the experiment predicted a rolling contact fatigue strength of 810 MPa with a standard deviation of 39.2 MPa, which differed from the experimental value by only 2.5%. Simulations of the rolling contact fatigue strength were then carried out while varying the traction coefficient. The contact force resulting in failure was observed to fall as the traction coefficient increased and the torque capacity increased. Thus, the torque capacity increases with the traction coefficient, regardless of changes in the rolling contact fatigue strength.

Keywords

• machine element
• traction drive
• rolling contact fatigue
• inclusion
• tribology
• shear stress